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<a name="Built_002dIn-Func_002fProc"></a>
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<p>
Next: <a href="M2-Constants.html#M2-Constants" accesskey="n" rel="next">M2 Constants</a>, Previous: <a href="M2-Operators.html#M2-Operators" accesskey="p" rel="prev">M2 Operators</a>, Up: <a href="Modula_002d2.html#Modula_002d2" accesskey="u" rel="up">Modula-2</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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<hr>
<a name="Built_002din-Functions-and-Procedures"></a>
<h4 class="subsubsection">15.4.9.2 Built-in Functions and Procedures</h4>
<a name="index-Modula_002d2-built_002dins"></a>

<p>Modula-2 also makes available several built-in procedures and functions.
In describing these, the following metavariables are used:
</p>
<dl compact="compact">
<dt><var>a</var></dt>
<dd><p>represents an <code>ARRAY</code> variable.
</p>
</dd>
<dt><var>c</var></dt>
<dd><p>represents a <code>CHAR</code> constant or variable.
</p>
</dd>
<dt><var>i</var></dt>
<dd><p>represents a variable or constant of integral type.
</p>
</dd>
<dt><var>m</var></dt>
<dd><p>represents an identifier that belongs to a set.  Generally used in the
same function with the metavariable <var>s</var>.  The type of <var>s</var> should
be <code>SET OF <var>mtype</var></code> (where <var>mtype</var> is the type of <var>m</var>).
</p>
</dd>
<dt><var>n</var></dt>
<dd><p>represents a variable or constant of integral or floating-point type.
</p>
</dd>
<dt><var>r</var></dt>
<dd><p>represents a variable or constant of floating-point type.
</p>
</dd>
<dt><var>t</var></dt>
<dd><p>represents a type.
</p>
</dd>
<dt><var>v</var></dt>
<dd><p>represents a variable.
</p>
</dd>
<dt><var>x</var></dt>
<dd><p>represents a variable or constant of one of many types.  See the
explanation of the function for details.
</p></dd>
</dl>

<p>All Modula-2 built-in procedures also return a result, described below.
</p>
<dl compact="compact">
<dt><code>ABS(<var>n</var>)</code></dt>
<dd><p>Returns the absolute value of <var>n</var>.
</p>
</dd>
<dt><code>CAP(<var>c</var>)</code></dt>
<dd><p>If <var>c</var> is a lower case letter, it returns its upper case
equivalent, otherwise it returns its argument.
</p>
</dd>
<dt><code>CHR(<var>i</var>)</code></dt>
<dd><p>Returns the character whose ordinal value is <var>i</var>.
</p>
</dd>
<dt><code>DEC(<var>v</var>)</code></dt>
<dd><p>Decrements the value in the variable <var>v</var> by one.  Returns the new value.
</p>
</dd>
<dt><code>DEC(<var>v</var>,<var>i</var>)</code></dt>
<dd><p>Decrements the value in the variable <var>v</var> by <var>i</var>.  Returns the
new value.
</p>
</dd>
<dt><code>EXCL(<var>m</var>,<var>s</var>)</code></dt>
<dd><p>Removes the element <var>m</var> from the set <var>s</var>.  Returns the new
set.
</p>
</dd>
<dt><code>FLOAT(<var>i</var>)</code></dt>
<dd><p>Returns the floating point equivalent of the integer <var>i</var>.
</p>
</dd>
<dt><code>HIGH(<var>a</var>)</code></dt>
<dd><p>Returns the index of the last member of <var>a</var>.
</p>
</dd>
<dt><code>INC(<var>v</var>)</code></dt>
<dd><p>Increments the value in the variable <var>v</var> by one.  Returns the new value.
</p>
</dd>
<dt><code>INC(<var>v</var>,<var>i</var>)</code></dt>
<dd><p>Increments the value in the variable <var>v</var> by <var>i</var>.  Returns the
new value.
</p>
</dd>
<dt><code>INCL(<var>m</var>,<var>s</var>)</code></dt>
<dd><p>Adds the element <var>m</var> to the set <var>s</var> if it is not already
there.  Returns the new set.
</p>
</dd>
<dt><code>MAX(<var>t</var>)</code></dt>
<dd><p>Returns the maximum value of the type <var>t</var>.
</p>
</dd>
<dt><code>MIN(<var>t</var>)</code></dt>
<dd><p>Returns the minimum value of the type <var>t</var>.
</p>
</dd>
<dt><code>ODD(<var>i</var>)</code></dt>
<dd><p>Returns boolean TRUE if <var>i</var> is an odd number.
</p>
</dd>
<dt><code>ORD(<var>x</var>)</code></dt>
<dd><p>Returns the ordinal value of its argument.  For example, the ordinal
value of a character is its <small>ASCII</small> value (on machines supporting
the <small>ASCII</small> character set).  The argument <var>x</var> must be of an
ordered type, which include integral, character and enumerated types.
</p>
</dd>
<dt><code>SIZE(<var>x</var>)</code></dt>
<dd><p>Returns the size of its argument.  The argument <var>x</var> can be a
variable or a type.
</p>
</dd>
<dt><code>TRUNC(<var>r</var>)</code></dt>
<dd><p>Returns the integral part of <var>r</var>.
</p>
</dd>
<dt><code>TSIZE(<var>x</var>)</code></dt>
<dd><p>Returns the size of its argument.  The argument <var>x</var> can be a
variable or a type.
</p>
</dd>
<dt><code>VAL(<var>t</var>,<var>i</var>)</code></dt>
<dd><p>Returns the member of the type <var>t</var> whose ordinal value is <var>i</var>.
</p></dd>
</dl>

<blockquote>
<p><em>Warning:</em>  Sets and their operations are not yet supported, so
<small>GDB</small> treats the use of procedures <code>INCL</code> and <code>EXCL</code> as
an error.
</p></blockquote>

<a name="index-Modula_002d2-constants"></a>
<hr>
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Next: <a href="M2-Constants.html#M2-Constants" accesskey="n" rel="next">M2 Constants</a>, Previous: <a href="M2-Operators.html#M2-Operators" accesskey="p" rel="prev">M2 Operators</a>, Up: <a href="Modula_002d2.html#Modula_002d2" accesskey="u" rel="up">Modula-2</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Concept-Index.html#Concept-Index" title="Index" rel="index">Index</a>]</p>
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